(Cat? OR feline) AND NOT dog?
Cat? W/5 behavior
(Cat? OR feline) AND traits
Cat AND charact*

This guide provides a more detailed description of the syntax that is supported along with examples.

This search box also supports the look-up of an IP.com Digital Signature (also referred to as Fingerprint); enter the 72-, 48-, or 32-character code to retrieve details of the associated file or submission.

Concept Search - What can I type?

For a concept search, you can enter phrases, sentences, or full paragraphs in English. For example, copy and paste the abstract of a patent application or paragraphs from an article.

Concept search eliminates the need for complex Boolean syntax to inform retrieval. Our Semantic Gist engine uses advanced cognitive semantic analysis to extract the meaning of data. This reduces the chances of missing valuable information, that may result from traditional keyword searching.

Ultra-resolution Image Transfer

Publishing Venue

IBM

Related People

Korth, HE: AUTHOR

Abstract

This article describes a new system for ultra-resolution photolithography. A combination of optical imaging and ultra-resolving scanning through a pair of pinhole arrays allows a mask to wafer image transfer which overcomes the classical diffraction limit. A resolution of 100 nm or better is achieved by using visible or near-UV light. Thus, the light wavelength is arbitrarily selectable for maximum efficiency (source, photoresist, optics, image field).

Country

United States

Language

English (United States)

This text was extracted from an ASCII text file.

This is the abbreviated version, containing approximately
38% of the total text.

Ultra-resolution Image Transfer

This article
describes a new system for ultra-resolution
photolithography. A combination of
optical imaging and
ultra-resolving scanning through a pair of pinhole arrays allows a
mask to wafer image transfer which overcomes the classical
diffraction limit. A resolution of 100
nm or better is achieved by
using visible or near-UV light. Thus,
the light wavelength is
arbitrarily selectable for maximum efficiency (source, photoresist,
optics, image field).

The structural
density of semiconductor devices is limited by
the physics of the photolithographic imaging process (Abbe
condition). The Abbe condition applies
only to imaging processes.
It is possible to feed light through a pinhole having a diameter of
only a fraction of the light wavelength.
If the pinhole is close to
a photosensitive surface, a pixel of similar dimension will be
generated.

A pinhole in
close vicinity to a photosensitive surface is used
to generate a spot image. The spot
diameter depends on the pinhole
diameter, the pinhole to object surface distance, and the
illumination. For small spots close to
the surface, the spot
diameter is considerably smaller than the wavelength of the
illuminating light. Controlled
sequential generation of such spot
images allows generating an arbitrary image pattern.

The pattern
to be imaged is stored on a mask. The
mask is
projected (demagnified) onto the object (wafer) surface. A conjugate
pinhole close to the mask is used to transmit only the desired pixel,
the rest of the mask being shielded. Even if the lateral resolution
of the imaging lens system is not as small as the pixel size, the
pixel is still resolvable at that stage.

Effective
exposure at a given object location depends on the
double convolution of the mask pattern with each of the conjugate
pinholes. The image contrast, which is
close to unity for extended
structures, decays rapidly to a value below 0.5 when the imaged line
width becomes smaller than the pinhole diameter. The depth of focus
of the system depends on the numerical aperture of the lens and the
gap between the pinhole carrier and the object surface. To generate
a smooth photosensitive surface on structured wafers, a planarization
layer may become necessary before the photoresist is applied.

Polarized
light causes an anisotropic coupling into the narrow
gap, so that focus and lateral resolution will also exhibit
anisotropy. This enhances the imaging
process in one direction still
further.

A multitude
of pixels may be transmitted in parallel by using a
pair of conjugate plates having a regular hexagonal or rectangular
pinhole array pattern. The pinholes must
be adequately spaced to
avoid crosstalk between adjacent pixels.

Linear
movement of the pinhole arrays relative to the image
allows covering all image locations.
This may be done in various
ways: A synchronous scann...